MySQL SyntaxError Exception: Unknown character set: 'utf8mb4' the problem occurs today when someone else's project is deployed and debugged. the following problem occurs: www.2cto.com Java code org. hibernate. exception. SQLGrammarException: Cannot open connection... root cause com. mysql. jdbc. exceptions. jdbc4.MySQLSyntaxErrorException: Unknown character set: 'utf8mb4' google. It is said that the Java code "create database 'test1' default character set utf8 COLLATE utf8_general_ci" is required to CREATE a DATABASE; also, the Java code <property name = "connection. url "> jdbc: mysql: // localhost: 3306/ssh_test </property> or <property name =" connection. characterEncoding "> UTF8 </property> also said that mysql6 to the new mysql-connector-j-5.1.13 version, which is used to 5.1.22 are not the last dialect by org. hibernate. dialect. change MySQLDialect to org. hibernate. dialect. mySQL5InnoDBDialect is OK